In-mold vibratile injection compression molding method and molding apparatus thereof

Abstract

An in-mold vibratile injection compression molding method and molding apparatus thereof are described. While performing a filling stage, a first piezoelectric actuator and a second piezoelectric actuator are use to vibrate the molding material along at least two directions for precisely filling the molding material into the micro-structure in order to avoid the form error, to increase the groove filling rate and to improve the residual stress.

What is claimed is: 
     
         1 . An in-mold vibratile injection compression molding method applicable to an in-mold vibratile injection compression molding apparatus, wherein the in-mold vibratile injection compression molding apparatus comprises a stationary structure, a fixed core, a movable unit comprising a movable core and a movable retainer, a pressure sensor, a first piezoelectric actuator, a second piezoelectric actuator, and wherein the fixed core is placed opposite to the movable core to form a cavity and the movable retainer has a guiding hole, the in-mold vibratile injection compression molding method comprising the steps of:
 (a) filling a molding material into the cavity;   (b) closing the movable core and the fixed core together such that the molding material is injected by the movable core to perform an injection compression process;   (c) sensing a pressure value of the cavity by the pressure sensor and outputting a pressure sensing signal;   (d) reciprocally propelling the movable core by the first piezoelectric actuator for reciprocally vibrating the movable core along a first direction in accordance with the pressure sensing signal when the pressure sensing signal is less than a peak pressure value of the cavity; and   (e) reciprocally propelling the movable core by the second piezoelectric actuator for reciprocally vibrating the movable core along a second direction in accordance with on the pressure sensing signal when the pressure sensing signal is less than the peak pressure value wherein the first direction is different from the second direction.   
     
     
         2 . The in-mold vibratile injection compression molding method of  claim 1 , wherein during the step (e), a recess is provided for containing the second piezoelectric actuator for reciprocally vibrating the movable core along the second direction, and the recess is provided in the place selected from one group consisting of a first annular recess of a periphery of the movable core, a second annular recess of the external periphery of the first piezoelectric actuator, a third annular recess of a sidewall of the guiding hole, a fourth annular recess within the movable retainer, a fifth annular recess of a periphery of the movable retainer and the combinations thereof. 
     
     
         3 . The in-mold vibratile injection compression molding method of  claim 1 , after the step (c), further comprising a step of: sensing a molding material temperature in the cavity by using a temperature sensor, and outputting a temperature sensing signal corresponding to the molding material temperature. 
     
     
         4 . An in-mold vibratile injection compression molding apparatus applicable to an injection molding equipment, the in-mold vibratile injection compression molding apparatus comprising:
 a stationary structure;   a fixed core disposed in the stationary structure and having a first end portion and a second end portion opposite to the first end portion;   a movable structure correspondingly disposed to the stationary structure for either separating from the stationary structure or contacting the stationary structure along a first direction, wherein the movable structure comprises a movable core having a third end portion and a fourth end portion corresponding to the third end portion, and a cavity is formed by the first end portion of the fixed core and the third end portion of the movable core to contain a molding material;   a pressure sensor disposed in the stationary structure and coupled to the fixed core for sensing a pressure value of the cavity and outputting a pressure sensing signal associated with the pressure value;   a first piezoelectric actuator disposed in the movable structure and coupled to the fourth end portion of the movable core for reciprocally vibrating the movable core along the first direction in accordance with the pressure sensing signal; and   a second piezoelectric actuator disposed in the movable structure for reciprocally vibrating the movable core along a second direction in accordance with the pressure sensing signal wherein the first direction is different from the second direction.   
     
     
         5 . The in-mold vibratile injection compression molding apparatus of  claim 4 , wherein either a first annular recess is provided on a periphery of the movable core or a second annular recess is provided on the external periphery of the first piezoelectric actuator to contain the second piezoelectric actuator. 
     
     
         6 . The in-mold vibratile injection compression molding apparatus of  claim 5 , wherein the first annular recess is adjacent to the third end portion such that the second piezoelectric actuator is adjacent to the cavity. 
     
     
         7 . The in-mold vibratile injection compression molding apparatus of  claim 4 , wherein the movable structure further comprises:
 a first sustaining plate correspondingly disposed to the stationary structure and having a first hollow hole;   a movable retainer, secured to the first hollow hole, having a guiding hole for reciprocally vibrating the movable core along the first direction within the guiding hole; and   a second sustaining plate secured to the first sustaining plate and the movable retainer, wherein the second sustaining plate comprises a second hollow hole for receive one end portion of the first piezoelectric actuator.   
     
     
         8 . The in-mold vibratile injection compression molding apparatus of  claim 7 , wherein a recess is provided for containing the second piezoelectric actuator, and the recess is provided in the place selected from one group consisting of a third annular recess of a sidewall of the guiding hole of the movable retainer, a fourth annular recess within the movable retainer, a fifth annular recess of a periphery of the movable retainer, a sixth fifth annular recess of a sidewall of the first hollow hole of the first sustaining plate and a seventh annular recess within the first sustaining plate. 
     
     
         9 . The in-mold vibratile injection compression molding apparatus of  claim 4 , wherein a surface of the first end portion of the fixed core is either an aspheric shape or a spherical shape corresponding to the cavity, and a surface of the third end portion of the movable core is a microstructure corresponding to the cavity. 
     
     
         10 . The in-mold vibratile injection compression molding apparatus of  claim 4 , further comprising a temperature sensor disposed in the stationary structure for sensing a molding material temperature in the cavity and outputting a temperature sensing signal corresponding to the molding material temperature.